Recently, research and development of digital copying machines has been enthusiastically pursued. A digital copying machine has a storage section for storing image data. The digital copying machine reads all images to be copied, and stores the image data obtained by the reading in the storage section. Thereafter, the image data are sequentially read out from the storage section to be printed. The digital copying machine executes a plural copy group mode and plural copy non-sort/non-staple mode by using such a memory function. In the plural copy group mode, when the first paper sheet (first page), in the order of originals, is printed in a designated number, these copies are discharged as one group. Subsequently, when the second paper sheet (second page) is printed in a designed number, these copies are discharged as one group (with discrimination among the respective groups). In the plural copy non-sort/non-staple mode, the first paper sheet (first page), in the order of originals, is printed in a designated number and discharged, and the second paper sheet (second page) is printed in a designated number and discharged in succession (without discrimination among the respective groups).
In the plural copy group mode and plural copy non-sort/non-stable mode using the above memory function, however, the copying machine sequentially starts printing images to be copied after all the images are read. For this reason, it takes much time before the first print operation starts.
The present invention has been made to solve the above problem, and has as its object to provide an image forming method and apparatus which can shorten the time required before the first print operation can be started while using a memory copying function.
(1) An image forming method of the present invention comprises the first step of reading a first image and writing first image data corresponding to the read image in a first memory area, the second step of compressing the first image data written in the first memory area in the first step and writing the data in a second memory area, the third step of storing, in an image data storage section, the compressed first image data written in the second memory area in the second step, the fourth step of reading out the first image data written in the first memory area and printing a predetermined number of copies of the first image based on the first image data concurrently with the second step, the fifth step of reading a second image following the first image and writing second image data corresponding to the read image in a third memory area, the sixth step of compressing the second image data written in the third memory area in the fifth step and writing the data in a fourth memory area, the seventh step of storing, in the image data storage section, the compressed second image data written in the fourth memory area in the sixth step, the eighth step of reading out the compressed second image data stored in the image data storage section and writing the data in the second memory area, the ninth step of decompressing the compressed second image data written in the second memory in the eighth step and writing the data in the first memory area, and the 10th step of reading out the decompressed second image data written in the first memory area in the ninth step and printing a predetermined number of copies of the second image based on the second image data.
(2) An image forming apparatus of the present invention comprises a scanner section for reading an image, first, second, third, and fourth memory areas for storing image data, an image data storage section for storing image data, a compression/decompression section for compressing and decompressing image data, a printer section for printing an image based on image data, and a control section for controlling processing from an image read by the scanner section to image printing by the printer section, the control means executing the first step of causing the scanner section to read a first image, and writing first image data corresponding to the read image in the first memory area, the second step of causing the compression/decompression section to compress the first image data written in the first memory area in the first step, and writing the data in the second memory area, the third step of storing, in the data storage section, the compressed first image data written in the second memory area in the second step, the fourth step of reading out the first image data written in the first memory area and causing the printer section to print a predetermined number of copies of the first image based on the first image data concurrently with the second step, the fifth step of causing the scanner section to read a second image following the first image, and writing second image data corresponding to the read image in the third memory area, the sixth step of causing the compression/decompression section to compress the second image data written in the third memory area in the fifth step, and writing the data in the fourth memory area, the seventh step of storing, in the image data storage section, the compressed second image data written in the fourth memory area in the sixth step, the eighth step of reading out the compressed second image data stored in the image data storage section and writing the data in the second memory area, the ninth step of causing the compression/decompression section to decompress the compressed second image data written in the second memory area in the eighth step, and writing the data in the first memory area, and the 10th step of reading out the decompressed second image data written in the first memory area in the ninth step, and causing the printer section to print a predetermined number of copies of the second image based on the second image data.